With the continuous evolution of wireless communication technologies and standards, mobile packet services develop significantly, and the data throughout capacity of a single terminal is being improved continuously. Taking Long Term Evolution (LTE) system as example, data transmission at a maximum downlink rate of 100 Mbps can be supported in a 20M bandwidth, and in the successive LTE advanced network, data transmission rate will be further increased, even up to 1 Gbps.
FIG. 1 is a schematic diagram illustrating an LTE user-plane protocol stack according to the conventional art, as shown in FIG. 1, the downlink data received from a core network via a GPRS Tunneling Protocol for the User Plane (GTP-U) is unpacked, processed by a Packet Data Convergence Protocol (PDCP) sub-layer, a Radio Link Control (RLC) protocol sub-layer, a Medium Access Control (MAC) protocol sub-layer and a Physical (PHY) layer and then sent to a User Equipment (UE), the sending of uplink data is an inverse process. At present, as the data transmission link between a network and a UE is a one-to-one dedicated link, the signal quality of the link and the resources occupied by the link decide the performance of the data transmission between the network and the UE. If the resources used by the link are limited or the signal quality of the link is poor, then the user experience of the UE is degraded, that is the big challenge mobile operators are facing, although network capacity is being continuously increased, the increase still cannot keep up with the increase in the number of user terminals or meet the demand of the users for data traffic.
To meet the increasing demand for data services while taking the unequal distribution of services in different regions into consideration, when deploying a new generation communication network (e.g. LTE), the operator adds Lower Power Node (LPN) (or referred to as Small Cell) to enhance hotspots. The increase of LPN cells complicates network deployment environment and gives rise to some problems. Although remarkably smaller in coverage range than Macro cells, LPN cells outnumber Macro cells, thus, frequent inter-cell handover occurs when a UE or terminal moves in a network, causing problems of frequent data services or even the call drop of a terminal which further lead to the reduction of the data throughout capacity of the user and the degradation of user experience. Meanwhile, the frequent handover also causes a large signaling impact to the terminal and the network (especially a core network), which may lead to the resource congestion or even the paralysis of a system. Moreover, the foregoing situation will get worse and worse as there are more and more LPN cells deployed by the operator and individuals.
No effective solution has been proposed to address the problem existing in the conventional art that the increase of the LPN cells deployed by the operator and individuals leads to the reduction of the data throughout of the user and the resource congestion or even the paralysis of a system.